1 /* 2 * 3 * V 4 L 2 D R I V E R H E L P E R A P I 4 * 5 * Moved from videodev2.h 6 * 7 * Some commonly needed functions for drivers (v4l2-common.o module) 8 */ 9 #ifndef _V4L2_DEV_H 10 #define _V4L2_DEV_H 11 12 #include <linux/poll.h> 13 #include <linux/fs.h> 14 #include <linux/device.h> 15 #include <linux/cdev.h> 16 #include <linux/mutex.h> 17 #include <linux/videodev2.h> 18 19 #define VIDEO_MAJOR 81 20 21 #define VFL_TYPE_GRABBER 0 22 #define VFL_TYPE_VBI 1 23 #define VFL_TYPE_RADIO 2 24 #define VFL_TYPE_MAX 3 25 26 struct v4l2_ioctl_callbacks; 27 struct video_device; 28 struct v4l2_device; 29 struct v4l2_ctrl_handler; 30 31 /* Flag to mark the video_device struct as registered. 32 Drivers can clear this flag if they want to block all future 33 device access. It is cleared by video_unregister_device. */ 34 #define V4L2_FL_REGISTERED (0) 35 #define V4L2_FL_USES_V4L2_FH (1) 36 37 struct v4l2_file_operations { 38 struct module *owner; 39 ssize_t (*read) (struct file *, char __user *, size_t, loff_t *); 40 ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *); 41 unsigned int (*poll) (struct file *, struct poll_table_struct *); 42 long (*ioctl) (struct file *, unsigned int, unsigned long); 43 long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long); 44 int (*mmap) (struct file *, struct vm_area_struct *); 45 int (*open) (struct file *); 46 int (*release) (struct file *); 47 }; 48 49 /* 50 * Newer version of video_device, handled by videodev2.c 51 * This version moves redundant code from video device code to 52 * the common handler 53 */ 54 55 struct video_device 56 { 57 /* device ops */ 58 const struct v4l2_file_operations *fops; 59 60 /* sysfs */ 61 struct device dev; /* v4l device */ 62 struct cdev *cdev; /* character device */ 63 64 /* Set either parent or v4l2_dev if your driver uses v4l2_device */ 65 struct device *parent; /* device parent */ 66 struct v4l2_device *v4l2_dev; /* v4l2_device parent */ 67 68 /* Control handler associated with this device node. May be NULL. */ 69 struct v4l2_ctrl_handler *ctrl_handler; 70 71 /* device info */ 72 char name[32]; 73 int vfl_type; 74 /* 'minor' is set to -1 if the registration failed */ 75 int minor; 76 u16 num; 77 /* use bitops to set/clear/test flags */ 78 unsigned long flags; 79 /* attribute to differentiate multiple indices on one physical device */ 80 int index; 81 82 /* V4L2 file handles */ 83 spinlock_t fh_lock; /* Lock for all v4l2_fhs */ 84 struct list_head fh_list; /* List of struct v4l2_fh */ 85 86 int debug; /* Activates debug level*/ 87 88 /* Video standard vars */ 89 v4l2_std_id tvnorms; /* Supported tv norms */ 90 v4l2_std_id current_norm; /* Current tvnorm */ 91 92 /* callbacks */ 93 void (*release)(struct video_device *vdev); 94 95 /* ioctl callbacks */ 96 const struct v4l2_ioctl_ops *ioctl_ops; 97 98 /* serialization lock */ 99 struct mutex *lock; 100 }; 101 102 /* dev to video-device */ 103 #define to_video_device(cd) container_of(cd, struct video_device, dev) 104 105 /* Register video devices. Note that if video_register_device fails, 106 the release() callback of the video_device structure is *not* called, so 107 the caller is responsible for freeing any data. Usually that means that 108 you call video_device_release() on failure. */ 109 int __must_check video_register_device(struct video_device *vdev, int type, int nr); 110 111 /* Same as video_register_device, but no warning is issued if the desired 112 device node number was already in use. */ 113 int __must_check video_register_device_no_warn(struct video_device *vdev, int type, int nr); 114 115 /* Unregister video devices. Will do nothing if vdev == NULL or 116 video_is_registered() returns false. */ 117 void video_unregister_device(struct video_device *vdev); 118 119 /* helper functions to alloc/release struct video_device, the 120 latter can also be used for video_device->release(). */ 121 struct video_device * __must_check video_device_alloc(void); 122 123 /* this release function frees the vdev pointer */ 124 void video_device_release(struct video_device *vdev); 125 126 /* this release function does nothing, use when the video_device is a 127 static global struct. Note that having a static video_device is 128 a dubious construction at best. */ 129 void video_device_release_empty(struct video_device *vdev); 130 131 /* helper functions to access driver private data. */ 132 static inline void *video_get_drvdata(struct video_device *vdev) 133 { 134 return dev_get_drvdata(&vdev->dev); 135 } 136 137 static inline void video_set_drvdata(struct video_device *vdev, void *data) 138 { 139 dev_set_drvdata(&vdev->dev, data); 140 } 141 142 struct video_device *video_devdata(struct file *file); 143 144 /* Combine video_get_drvdata and video_devdata as this is 145 used very often. */ 146 static inline void *video_drvdata(struct file *file) 147 { 148 return video_get_drvdata(video_devdata(file)); 149 } 150 151 static inline const char *video_device_node_name(struct video_device *vdev) 152 { 153 return dev_name(&vdev->dev); 154 } 155 156 static inline int video_is_registered(struct video_device *vdev) 157 { 158 return test_bit(V4L2_FL_REGISTERED, &vdev->flags); 159 } 160 161 #endif /* _V4L2_DEV_H */ 162